> Got it working.
>
> I had to add the networks for the schools under mynetworks. That with
> relay_domains, and transport configured got things working.
>
> Thanks for the help!
>

Adding IP's to mynetworks bypasses the relay check and just allows them
full access to relay to any domain
http://www.postfix.org/postconf.5.html#mynetworks

The way to best help would be if you provided the output of postconf -n